Polysubstituted High-Entropy [LaNd](Cr<sub>0.2</sub>Mn<sub>0.2</sub>Fe<sub>0.2</sub>Co<sub>0.2</sub>Ni<sub>0.2</sub>)O<sub>3</sub> Perovskites: Correlation of the Electrical and Magnetic Properties
Vladimir E. Zhivulin,
Evgeniy A. Trofimov,
Svetlana A. Gudkova,
Igor Yu. Pashkeev,
Alexander Yu. Punda,
Maksim Gavrilyak,
Olga V. Zaitseva,
Sergey V. Taskaev,
Fedor V. Podgornov,
Moustafa A. Darwish,
Munirah A. Almessiere,
Yassine Slimani,
Abdulhadi Baykal,
Sergei V. Trukhanov,
Alex V. Trukhanov,
Denis A. Vinnik
Affiliations
Vladimir E. Zhivulin
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Evgeniy A. Trofimov
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Svetlana A. Gudkova
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Igor Yu. Pashkeev
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Alexander Yu. Punda
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Maksim Gavrilyak
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Olga V. Zaitseva
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Sergey V. Taskaev
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Fedor V. Podgornov
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Moustafa A. Darwish
Department of Technology of Electronics Materials, National University of Science and Technology MISiS, Leninsky Prospekt 4, 119049 Moscow, Russia
Munirah A. Almessiere
Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
Yassine Slimani
Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
Abdulhadi Baykal
Department of Nanomedicine Research, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
Sergei V. Trukhanov
Department of Technology of Electronics Materials, National University of Science and Technology MISiS, Leninsky Prospekt 4, 119049 Moscow, Russia
Alex V. Trukhanov
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
Denis A. Vinnik
Laboratory of Single Crystal Growth, South Ural State University, 454080 Chelyabinsk, Russia
La-, Nd- and La/Nd-based polysubstituted high-entropy oxides (HEOs) were produced by solid-state reactions. Composition of the B-site was fixed for all samples (Cr0.2Mn0.2Fe0.2Co0.2Ni0.2) with varying of A-site cation (La, Nd and La0.5Nd0.5). Nominal chemical composition of the HEOs correlates well with initial calculated stoichiometry. All produced samples are single phase with perovskite-like structure. Average particle size is critically dependent on chemical composition. Minimal average particle size (~400 nm) was observed for the La-based sample and maximal average particle size (5.8 μm) was observed for the Nd-based sample. The values of the configurational entropy of mixing for each sample were calculated. Electrical properties were investigated in the wide range of temperatures (150–450 K) and frequencies (10−1–107 Hz). Results are discussed in terms of the variable range hopping and the small polaron hopping mechanisms. Magnetic properties were analyzed from the temperature and field dependences of the specific magnetization. The frustrated state of the spin subsystem was observed, and it can be a result of the increasing entropy state. From the Zero-Field-Cooling and Field-Cooling regimes (ZFC-FC) curves, we determine the average and Smax maximum size of a ferromagnetic nanocluster in a paramagnetic matrix. The average size of a ferromagnetic cluster is ~100 nm (La-CMFCNO) and ~60 nm (LN-CMFCNO). The Smax maximum size is ~210 nm (La-CMFCNO) and ~205 nm (LN-CMFCNO). For Nd-CMFCNO, spin glass state (ferromagnetic cluster lower than 30 nm) was observed due to f-d exchange at low temperatures.
